diff --git a/python_module/setup.py b/python_module/setup.py
index 5a662cc84ad8dc54819287079cd515256c59870f..43e72d7aab819b8a1cc69f6569d682df5dbdd822 100644
--- a/python_module/setup.py
+++ b/python_module/setup.py
@@ -87,6 +87,9 @@ setup_kwargs = dict(
         'data': [
             'scipy',
         ],
+        'ci': [
+            'pytest==5.3.0',
+        ],
     },
     cmdclass={'build_ext': build_ext},
 )
diff --git a/python_module/src/cpp/function_replace.cpp b/python_module/src/cpp/function_replace.cpp
index 75571429627dbaa0167625f02d529ecdea79fd3b..cbd59790ae1b0e4fce933bd8382575598473d969 100644
--- a/python_module/src/cpp/function_replace.cpp
+++ b/python_module/src/cpp/function_replace.cpp
@@ -35,7 +35,6 @@ void throw_fork_cuda_exc() {
     // call chain:
     // python -> fork() -> pthread_atfork -> CudaCheckOnFork ->
     // ForkAfterCudaError::throw_
-    GILManager a;
     mgb_log_warn("try to raise python exception for fork after cuda");
     PyErr_SetString(PyExc_SystemError, "fork after cuda has been initialized");
 }